Expendable screw mortar



y 1962 N. K. TURNBULL ETA]. 3,031,931

' EXPENDABLE SCREW MORTAR Filed Dec. 4, 1958 F|G.3. FIG. 2.

l6 Q 4 Q l8 q FIG.4.

INVENTOR. N. K. TURNBULL HENRY KAHN ATTORNEYS;

. 3,031,931 EXPENDABLE SCREW MORTAR Norman K. Tnrnbuil, Pitman, N.J., and Henry Kahn,

Levittown, Pa, assignors to the United States of Amerion as represented by the Secretary of the Army Filed Dec. 4, 1958, Ser. No. 778,266

3 Claims. (Cl. 89-1) 7 (Granted under Title 35, US. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.

This invention relates to mortars, and more especially to an improved mortar which may be manufactured inexpensively, is in a concealed position during its use, and may be left by its operator in a condition to function as a booby trap.

The present invention attains these advantages by means of an auger-shaped tube of light metal. This tube has at one of its ends a closure in the form of a pointed cone and at its other end means by which it may be bored into the earth. Located near the base of the cone is a firing pin upon which the primer of the projectile impacts when it is dropped down the tube.

The invention will be better understood from the following description when considered in connection with the accompanying drawings and its scope is indicated by the appended claims.

Referring to the drawings:

FIG. 1 is a side view of the mortar, 7

FIG. 2 is an end view indicating the contour of the hand grip by means of which the mortar is threaded into the earth,

FIG. 3 is a sectional view of the cone, and

FIG. 4 illustrates the aiming device of the mortar.

The mortar of FIG. 1 includes a light metal tube with a thread 11 as an integral part of its outer periphery. A pointed cone 12 is fixed to one end of the tube 10. At its other end is a plate 13 which forms a hand hold for threading the mortar into the earth. As shown more clearly by FIG. 3, the cone 12 has fixed to its base a member 14 upon which is supported a firing pin 15.

It can be seen that the thread 11 extends from the cone 12 for approximately three-fourths the length of the tube 10. This is to leave space for a quadrant 16 to be stamped on the tube. Adjacent this quadrant is a small hole 17 arranged to receive the pivot pin 18 of an angle indicator 19.

In use of the mortar, the tube is screwed into the earth at a desired angle which is indicated by the indicator 19. Thereafter the indicator is removed and the tube may be screwed deeper into the ground as desired. Firing of the mortar is effected by dropping the projectile into the tube 3,31,931 Patented May 1, 1962 so that its primer impacts the firing pin 15. The shouldered end 13 of the tube acts to prevent the mortar from digging in during firing.

The mortar may be placed in the ground vertically with a shell wedged in its mouth to form a tank, or booby-trap. Being made of light metal tubings and stampings, the mortar is economical to manufacture and need not be removed from the ground after its use. Obviously the mortar may be preheated and thereafter positioned in We claim:

1. An expendable mortar having a thin-walled tubular portion for guiding a projectile, a closed base at one end of said tubular portion, said tubular-portion having an open mouth at the other end, said tubular portion being hollow along its entire length from said open mouth end to said closed base, said base having a fixed firing pin therein for impacting and firing a projectile dropped into said open month, said closed base being shaped externally in the form of a cone, said tubular portion having an external shape in the form of an anger extending a major part of the length of said tubular portion, the remaining external part of said tubular portion being smooth, grip ping means fastened to and surrounding the uppermost portion of said open mouth of said tubular portion, said gripping means comprising a thin plate having an opening therethrough' aligned with said open mouth of said tubular portion whereby said mortar may be angered into an earth emplacement to a depth limited by said gripping means to thereby expose only the open mouth and gripping means such that the tubular portion is substantially entirely supported by the earth emplacement surrounding it to enable the wall thickness of said tubular portion to be thin walled since the earth aids in withstanding firing pressures otherwise withstood by thicker walled mortars.

2. A mortar according to claim 1 wherein said remaining external part of said tubular portion bears a quadrant having one of its sides perpendicular to the axis of said References Cited the file of this patent UNITED STATES PATENTS 716,158 Wheeler Dec. 16, 1902 1,198,398 Wicker Sept. 12, 1916 1,334,413 Stokes Mar. 23, 1 920 2,330,205 Cox Sept. 28, 1943 2,445,326 Janney -1 July 20, 1948 

